Apparatus for feeding a preselected length of wire



H. K. EMBREE July 14, 959' APPARATUS FOR FEEDING A PRESELECTED LENGTH OF WIRE Filed m 28, 1957 2 Sheets-Sheet 1 INVENTOR F. E U R N B WR M Ov run 0W D L M 0 R A H% Y B July 14, 1959 H. K. EMBREE 2,894,617

APPARATUS FOR-FEEDING A PRESELECTED LENGTH OF WIRE Filed May 28, 1957 2 Sheets-Sheet 2 INVENTOR HAROLD K. EMBREE BY, 4/1p41 ATTORN YS.

United Stt APPARATUS FOR FEEDING A PRESELECTED LENGTH OF WIRE Harold K. Embree, Hamilton, Ontario, Canada, assignor to 'Ovalstrapping Inc., Hoquiam, Wash, a corporation of Washington Application May 28, 1957, Serial No. 662,033

6 Claims. (Cl. 203-240) This invention relates to anapparatus for feeding a preselected length of wire from a wire storage mechanism. The apparatus of the invention is particularly useful for feeding desired lengths of wire strapping to a package baling operation.

In the baling of a number of similarly sized packages the operator of the wire tying machine has va repeated requirement fora fixed length of strapping or baling wire which will enable him to encircle the package, and then tension and tie the wire.

Accordingly, it is an object of the present invention to provide a feeding device which will conveniently feed a length of strapping or baling wire from storage to the operator.

It is a further object of the invention to provide means on the device whereby the length of the length of strapping or baling wire so fed to the operator can be pre determined, thereby providing for the feeding of longer or shorter lengths of wire when different sized packages are present for baling.

The wire feeding device of my invention comprises a casing, a pair of rolls of similar diameter rotatably mounted adjacent one another within said casing, resilient means urging said rolls into tangential contact with one another, similarly sized but oppositely directed helical grooving on each of said rolls, said grooving being suitably sized for co-operative gripping between the rolls of the wire which is to be fed, means for driving said rotatably mounted rolls in opposite directions but at the same speed, and shielding means adjustably mounted on said casing, said shielding means being adjustable longitudinally of the line of tangential contact of the pair of rolls to limit the length of said line of contact which is exposed for insertion of a wire between said rolls.

It will be appreciated that with such a device, wire which has been introduced between the helically grooved rolls will be fed forward, i.e. withdrawn from storage, as the rolls rotate. While the rolls rotate constantly, the wire will not be fed constantly, since, due to the helical nature of the grooving, the wire, once inserted in the grooving, will move in regular fashion towards the point where it will be dropped by the two rolls, i.e. cast out of the rolls by the grooving at the bases thereof. It will also be readily appreciated that the greater the length of the line of tangential contact of the rolls which is traversed by the wire, the longer will be the length of wire drawn off the storage means. It is of course the function of the above-mentioned shield to impose limits upon the length of the line of tangential contact of the rolls available at any given time for traversing by the wire. The operator simply inserts the wire between the grooved rolls with the wire pressing against the portion of shield nearest the rolls; and the distance of said portion from the bases of the rolls will automatically determine the amount of wire which will be stripped off the storage means by the grooved rolls.

The aforementioned and other objects of this invention will become apparent from a study of the following detailed description of two examples of embodiments of the invention, reference being had in the said description to the accompanying drawings.

In these drawings:

Figure 1 is a side elevation of one embodiment,

Figure 2 is a cross-section taken along the line 22 in Figure 1,

Figure 3 is a front elevation,

Figure 4 is a partial top plan view,

Figure 5 is a sectional detail showing one form of helical grooving on the feed rolls, and

Figure 6 is a diagrammatic representation of an alternative arrangement of the grooved rolls, wherein the rolls are frusto-conical instead of cylindrical as in the preceding figures.

Turning to the drawings .and considering them in detail, it will be noted that the grooved feed rolls to be described in greater detail later on, are mounted within a generally rectangular casing which has been generally indicated by reference numeral 10 and is made up of a backplate 11, a front casting 12, spacer plates 13, located at opposite sides of the casing, and an L-shaped mounting plate 14. The casing, when assembled, is held together by a plurality of threaded bolts 15 which are screwed into suitably threaded bores provided in the front casting 12.

A fixed bearing block 16 is mounted within the casing so as to be fixed with respect thereto by means of a dowel pin 17 and two bolts 18, all of which may be noted at the left-l1and side of Figure 2. A driving shaft 19 is rotatably mounted within bearing block 16 by means of two spaced-apart ball bearings 20. The upper ball bearing is located by means of a snap ring 21 held in suitable grooves provided in bore 22 of the fixed bearing block 16. The lower ball bearing is spaced from the upper ball bearing by means of a cylindrical spacer 23 which is concentrically mounted on the driving shaft 19. A cylindrical roll 25 is fixed upon the lower end of the driving shaft 19 by means of a key 26 and a nut 27 which bears against a washer 28. It will be noted that the lower ball bearing 29 is held between the lower end of the spacer 23 and the upper end of the roll 25.

A bearing block 29 is floatably mounted within the casing beside fixed bearing block 16. Bearing block 29 is pivotally mounted upon the back plate 11 of the casing as indicated at 30 in Figures 1 and 2; and is urged into contact with the bearing block 16 by means ot a compression spring 31 which is inserted in a bore 32 provided in the bearing block 29 and is compressed against the inner wall of the spacer plate 13 adjacent the floating bearing block. A driven shaft 33 is mounted within the floating bearing block 29 by means of two spaced-apart ball bearings 34. The upper ball bearings 34 are held in position by means of a snap ring 35 located in suitable grooves provided in bore 36 of the floating bearing block 29. The lower end of the driven shaft 33 carries a feed roll 37 which is similar to feed roll 25 and is held in position on the driven shaft by means of a key 38 and a nut 39 which bears against a washer 40. A bearing spacer 41 is concentrically mounted upon the driven shaft 33 and serves to space the two bearings 34 while at the same time sandwiching the lower ball bearing 34 between the upper end of the feed roll 37 and the lower end of the spacer 41. The bearing spacer 41 is, of course, concentrically mounted upon the driven shaft 33 just as bearing spacer 23 was mounted upon the driving shaft 19.

A drive gear 42 is keyed to the driving shaft 19 at a point just above the upper ball bearing 20 and a driven gear 43 is keyed to the driven shaft 33 at a point just above the upper ball bearing 34. The gears 42 and 43 are similar to one another and in mesh with one another so as to provide direct drive between the driving shaft 19 and the driven shaft 33, whereby the two shafts and the two rolls carried thereby will be driven at the same rate of speed but in opposite directions whenever shaft 19 is rotated.

A shield 44 is adjustably mounted upon the front wall of the casing. The shield 44 is a plate-like member in the shape of an L which has a rectangular vertical arm 45 and a generally triangular horizontal arm 46. The rectangular arm 45 is adjustably mounted upon the front wall of the casing by means of two knurled thumb screws 47 which pass through bores in the mounting plate 14 and enter threaded bores in the front casting 12, the arm 45 itself being provided with two vertical slots 48. To adjust the position of the shield member one simply loosens the two knurled thumb screws 47 and, by virtue of the slots 48, slides the arm 45 to the desired adjusted position, whereupon the thumb screws 47 may be tightened down to clamp the arm 45 between the mounting plate and suitable washers 49 carried by the thumb screws. It will be noted from Figure 4 that the horizontal arm 46 of the shield 44 extends inwardly to a point just short of the line of tangential contact of the rolls 25 and 37. It will be appreciated that, with such a shaped shield, it would be impossible to inadvertently insert the wire between the rolls at a point above the point of location of the shield.

Turning now to Figure 5, it is pointed out that each of the rolls 25 and 37 is provided with helical grooving as indicated at 49. The helical grooving 49 preferably extends from end to end in each roll. The grooving 49 is similar in each roll except for the fact that one roll is provided with a left-hand helix while the other uses a right-hand helix. It is essential to the invention that the helices of the grooves 49 be oppositely directed. It will also be realized, of course, that the helical grooving 49 in the two rolls must be so related to the direction of rotation of the driving and driven shaft that wire being fed through the rolls will, as the rolls rotate, move in a direction away from the bearing blocks.

Figure 5 illustrates a particular shape of grooving which has been found desirable for use in conjunction with the feeding of oval-shaped strapping wire having a major dimension of .110 inch and a minor dimension of .054 inch, using cylindrical rolls having a diameter of 2 inches and a height of about 2 /4 inches. With this wire I found it desirable to have an inter-groove (center to center) spacing of .100 inch and to provide V-shaped grooves having an apex angle of about 40 and a mouthwidth of approximately .060 inch.

It will be appreciated that the cylindrical rolls disclosed in the figures described so far will deliver the wire at a constant rate of speed, provided the driving shaft 19 is rotated at a constant speed. For certain applications, however, the use of such cylindrical rolls may mean that the wire leaves the rolls while travelling at an undesirably high rate of speed. Where such is the case, resort can be made to the arrangement diagrammatically shown in Figure 6. In the arrangement according to Figure 6, the cylindrical rolls 25 and 37 of Figures 1-5 would be replaced by rolls 25A and 37A of truncated conical formation, and some further rearrangement of parts would be necessary due to the fact that the driving and driven shafts would not be parallel in the arrangement of Figure 6. However, those skilled in the mechanical arts would have no ditficulty in redesigning the casing, hearing blocks, etc., of the previously desribed figures to accommodate the change from cylindrical to truncated conical rolls. The value of employing the conical rolls of course resides in the fact that while the wire will be fed quickly when inserted near the top of the line of tangential contact of the rolls 25A and 37A, it will travel progressively more slowly as it works its way toward the bases of the cones 25A and 37A, so that it will be travelling quite slowly when it is dropped out of the rolls.

While I have, by way of example, described and shown (Figure 5) rolls grooved for the feeding of wire of oval cross-section, it will be appreciated the device of the in vention would be equally well suited to the feeding of wire or strapping of circular cross-section.

What I claim as my invention is:

1. An apparatus for feeding a preselected length of wire comprising a case, a pair of rolls of similar diameter rotatably mounted adjacent one another within said casing, resilient means urging said rolls into tangential contact with one another, similarly sized but oppositely directed helical grooving on each of said rolls, said grooving being suitably sized for co-operative gripping between the rolls of the wire which is to be fed, means for driving said rotatably mounted rolls in opposite directions but at the same speed, and shielding means adjustably mounted on said casing, said shielding means being adjustable longitudinally of the line of tangential contact of the pair of rolls to limit the length of said line of contact which is exposed for insertion of a wire between said rolls.

2. A wire feeding apparatus as defined in claim 1, in which each of said rolls is mounted in a bearing block disposed within said casing, one of said blocks being rigidly fixed with respect to the casing, the other of said bearing blocks being a floating block, and in which said resilient means comprises a compression spring acting between said casing and said floating bearing block to urge the roll supported by the floating bearing block into tangential contact with the roll supported by the fixed bearing block.

3. A wire feeding means as defined in claim 1, in which said casing is arranged so that said line of tangential contact extends vertically.

4. A wire feeding means as defined in claim 1, in which said rolls are cylindrical.

5. A wire feeding means as defined in claim 1, in which said rolls are frustoconica1.

6. A wire feeding means as defined in claim 1, in which the shielding means comprises an L-shaped plate, one arm of the L-shaped plate being adjustably mounted on said casing, the other arm extending inwardly to a point just short of the line of tangential contact of said rolls.

References (Iited in the file of this patent UNITED STATES PATENTS 2,754,958 Murrell et al. July 17, 1956 FOREIGN PATENTS 539,200 Great Britain Sept. 1, 1941 

